Door closer



June 14, 1966 R. c. FLINT 3,255,482

DOOR CLOSER Filed Jan. 18, 1962 4 Sheets-Sheet l June 14, 1966 R. c. FLlN-r 3,255,482

DOOR CLOSER FIG. 4

0 all INV Russell C. Flinl June 14, 1966 R. c. FLlN-r 3,255,482

DOOR CLOSER 4 Sheets-Sheet 3 FIG 1A n2 Co GA/ 7A FIG. 6

FIG. 6A

INVENTOR.

Russell C FIinT @W M, uw 9L M AHys.

June 14, 1966 R. c. FLINT 3,255,482

DOOR CLOSER BY @www :4L/M, Mw f Mumi- Arrys.

, d v r' 3,255,482 Unlte States Patent O ce Patente, ,une ,4, 66

of the pistons and paths of fluid travel during the general 3,255,482 speed stage;

DOOR CLOSER Russell C. Flint, Princeton, Ill., assignor to Schlage Lock Company, San Francisco, Calif., a corporation of California Filed Jan. 18, 1962, Ser. No. 167,069 Claims. (Cl. 16-62) This invention relates to a new and improved door closer and, more particularly, to a door closer of the spring and fluid checking type having a plurality of pistons.

It is an object of the present invention to provide a door closer device to control the opening and closing of a door.

- It is a further object of the present invention to provide a door closer having a plurality of pistons which operate in separate piston chambers and are activated by separate piston shafts.

It is a further object of the present invention to provide a door closer having a plurality of pistons which operate in separate piston chambers and an associated valve arrangement adapted to control the opening and closing of a door. t

It is a further object of the present invention to provide a door closer having a plurality of valve free pistons which operate in separate piston chambers to control the opening and closing of a door.

It is a further object of the present invention to provide in a door closer having a plurality of pistons which operate in separate piston chambers, a reservoir arrangement which will equalize the displacement differentials of'the piston chambersy It is a further object of the present invention to provide a door closer which controls the opening and closing of a door by a valving arrangement contained in a cartridge which may be inserted into the door closer.

It is a further object of the present invention to provide a door closer containing a plurality of pistons in separate chambers wherein each piston is mounted upon its piston shaft i-n such a manner that the piston chamber need not Ibe concentric with the bore housing the cooperating piston shafts.

It is a further object of the present invention to provide a door closer which may be mounted in a narrow head frame of a door frame.

The invention, both as to its organization and method of operation, taken with further objects and advantages thereof, will best be understood by reference to the following description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a perspective View of a door closer embodyiug the features of the present invention mounted within a door frame and operatively connected to a door;

FIGURE 2 is a top cross-sectional View of the door closer of FIGURE 1;

FIGURE 3 is a side cross-sectional view of the door closer of FIGURE 1 taken along line 3-3 of FIGURE 2;

FIGURE 4 is a fragmentary top cross-sectional view of the door closer of FIGURE 1 illustrating the position vof the pistons and the paths of fluid travel during the initial dooreopening stage;

FIGURE 4A is a side cross-sectional view of FIGURE 4 taken along lines 4A--4A of FIGURE 4;

FIGURE 5 is a fragmentary top cross-sectional view of the door closer of FIGURE l illustrating the position of the pistons and the paths of uid travel as the door is opening in the back check stage;

.FIGURE 5A is a side cross-sectional view of FIGURE 5 taken along lines SA-SA of FIGURE 5;

FIGURE 6 is a fragmentary top cross-sectional view of the door closer of FIGURE 1 illustrating the position FIGURE 8 is a fragmentary top cross-sectional view i of the door closer of FIGURE 1 which has been adjusted for Va quick release stage, illustrating the position of the pistons and paths of lluid travel as the door is in the quick release stage;

FIGURE 8A is a side cross-sectional view taken along lines 8A-8A of FIGURE 8; i

FIGURE 9 is a fragmentary top cross-sectional View of a modified door closer of the present invention containing a cartridge-type valving arrangement;

FIGURElO is a side cross-sectional view of the embodiment of the door closer shown in FIGURE 9 taken along lines 10-10 of FIGURE 9.

FIGURE 11 is a side cross-sectional view of amodified piston suitable for use in the door closer illustrated in FIGURE l; and

FIGURE 12 is a top, partial cross-sectional view of the modified piston of FIGURE 11.

Referring now to the drawings, and more particularly to FIGURE 1, the door closer of the present invention, referred to generally by reference numeral 20, is illustrated operatively connected to a door 22 hinged at 24 to a door frame, The head frame 28 of the door frame illustrated in FIGURE 1 is a 1% X 4 x 1A extruded aluminum head frame, though it will be understood that any otherhead frame may be employed With the closer 20 of the present invention. It i-s the function of the door closer 20 to control the speed and ease with which the door 22 is opened and closed. Furthermore, the door closer 20 functions to assure proper door latching without the door 22 slamming into the door frame. To these ends the door closer 20 permits the door 22 to open at `a relatively rapid rate in response to the push or pull of the person opening the door 22. This is hereinafter referred to as the initial door-opening stage. However, once the door 22 has swung through a controllable predetermined arc, such as about 70, the door enters the stage hereinafter referred to as the back check stage. That is, the door closer 20 is adapted to increase the amount of force necessary to open the door 22 past this predetermined arc and to reduce the opening speed of the door 22 during this back check stage. The door 22 is thereby prevented from being easily pushed or pulled open in such a manner that it bangs into an adjacent wall.

Once the door 22 has completed its opening operation, the door closer 20 permits the door 22 to close at a rapid or slow speed, as desired, until it has returned relatively close to the door frame. This stage is hereinafter referred to as the general speed stage. After completing this stage, the door 22 goes through the final stage of its closing operation in which it latches in the door frame. Thus if the door 22 during the general speed stage has been lclosing at a rapid rate, the door closer 20, in effect, brakes the speed of the door 22 to assure that it will not bang or slam into the door frame and yet properly latch, which is referred to 4hereinafter as the latching speed stage. On the other hand, if the door closer 20 has been set so that during the general speed stage the door 22 is closing very slowly, then the door closer 20 allows the door 22 to speed up sufficiently to assure proper latching, which is hereinafter referred to as the quick release stage.

In this connection, the operative cooperation between the door 22 and the closer 20 is effected by an arm 30. One end of the arm 30 is atta-ched to a rotatable shaft 34 extending from the door closer 20 and the other end of arm 30 is pivotally mounted upon a stud 38 or'the like which is slidably mounted in the upper portion of the door 22. As the door 22 opens and the stud 38 slides in the door 22, the arm 30 rotates the shaft 34. Likewise, as the door 22 closes the movement of the arm 30 will rotate the shaftl 34 in the opposite direction. In this arrangement, the shaft 34 must be rotated when the door 22 opens or closes. Therefore the door closer 20, by controlling the speed of rotation of the shaft 34, controls the opening and closing speed of the door 22.

The manner in which the door closer 20 of the present invention controls the Irotational speed of the shaft 34 and thereby the opening and closing of the door 22 will be considered in more detail with reference to FIGURES 2 through 8A. Referring specifically to FIGURES 2 and 3, the door closer 20 comprises a housing 40 having a pair of cylindrical piston chambers 42 and 44 closed by caps 82 in which pistons 46 and 48, respectively, operate. The piston chambers 42 and 44 are substantially parallel to one another and have interposed therebetween a valving arrangement indicated generally by reference numeral 41. The pistons 46 and 48 are connected to piston shafts 50 and 52, respectively, which are slidably mounted in cylindrical bores 58 and 60, respectively, in the housing 40. One end of the bores 58 and 60 communicates with the piston chambers 42y and 44, respectively, the other ends being sealed olf by caps 61. Sealing means 81 are provided in the cylindrical bores 58 and 60 and cooperate with the piston shafts 50 and 52, respectively, to prevent uid from the piston chambers from entering these cy- `lindrical bores. The cylindrical bores 58 and 60 are substantially parallel to one another and have substantially the same longitudinal axis as their associated piston chambers 42 and 44, respectively. It is difficult when machining the housing 40 to concentrically align the bore' 58 with the piston chamber 42 and the cylindrical bore 60 with the piston chamber 44. It is a feature of the present invention, which Will be more specifically discussed hereinafter, that the construction of pistons 46 and 48 assures proper operation of the door closer 20 even when such alignment has not been achieved.

The shaft 34 extends into and is rotatably mounted within the housing 40 and carries a gear 62 which is in meshing engagement with a gear 64 on a shaft 66 rotatably mounted Within the housing 40. The gears 64 and 62 are in meshing engagement with rack teeth 54 on piston shaft 50 and rack teeth 56 on piston shaft 52, respectively. Thus when the shaft 34 and the gear 62 are rotated in a counterclockwise direction as viewed in FIGURE 2, t-he gear 64 rotates in a clockwise direction and the gears 62 and 64 move the pistons 48 and 46, respectively, toward the right. This occurs as the door is being opened. Likewise, when the door is closing, the shaft 34 and gear 62 are rotated in a clockwise direction causing the gear 64 to rotate in a counterclockwise direction whereby pistons 46 and 48 travel to the left as viewed in FIGURE 2.

The piston 48, as may be seen in FIGURE 2, comprises an annular piston head 68 which is mounted upon a cylindrical'ly shaped projection or `stud 70 connected to and extending longitudinally from piston shaft 52. The projection 70 is of a lesser diameter than the piston shaft 52. The internal diameter of the piston head 68 is larger than the diameter of the projection 70, but smaller than the diameter of the piston shaft 52. The piston head 68 and an vO-ring seal 80 located at the juncture of the piston lshaft 52 and the projection 70 are prevented from longitudinally moving upon projection 70 by a snap ring 72 which fits into a groove or notch on the free end of the projection 70. The O-ring seal 80 maintains a hydraulic seal between the ends of the piston 48. Rotational larger internal diameter than the diameter of the projection '78, it is also free to a limited extent to move radially about the projection 70. Therefore, the piston head 68 oats upon the projection 70 and will properly position itself within the piston chamber 44 even if the piston chamber 44 is not aligned concentrically with the bore 60 in which the piston shaft 52 is located. In this manner the piston 48 is maintained in fluid tight engagement with the walls of the piston chamber 44. The piston 46 is constructed in the same manner as piston 48 for these reasons.

The door closer 20 is of the fluid and spring checking type. That is a spring and hydraulic fluid are the means by which the door closer 20 is able to control the opening and closing of the door 22 operatively connected thereto..

In this connection, the piston chambers 42 and 44 and the valving arrangement 41 are lled with fluid. The pistons 46 and 48 must therefore displace fluid from their piston chambers to move left or right. To this end the valving arrangement 41 is provided whereby the pistons 46 and 48 displace uid from the forward end of their piston chambers, the end toward which the pistons are moving, through the valving arrangement 41 and generally back to the piston chambers on the other or trailing side of the pistons 46 and 48. The piston chambers 42 and 44 are therefore always full of hydraulic Huid. Furthermore, in this manner the valving arrangement 41 determines the ease or difficulty with which this fluid by-passing occurs and therefore the ease or difficulty with which the pistons 46 and 48 may be moved, which controls in turn the movement of the door 22 to which the door closer 20 is operatively connected.

In addition to the ycontrol 'effected through the fluid system, a spring 84 assists the door closer 20 to perform its intended functions. The spring 84 is located in the piston chamber 44 and acts against the piston 48 and a spring adjustment means 86, the latter forming no part of the instant invention. Therefore, the spring 84 continually resists movement of the piston toward the right as shown in FIGURE 2 and thus is one force which must be overcome in pushing or pulling Ithe door 22 open. The spring 84 provides the force necessary to close the door 22. The spring adjustment means 86 may be adjusted to increase or decrease the force it exerts upon the piston 48.

More specifically, the valving arrangement 41 is interposed between the piston chambers 42 and 44. It comprises a plurality of transverse passageways `88, 90, 92 and 94 in the housing 40, each of which communicate with both the piston chambers 42 and 44. A channel or groove 91 is in the wall of both the piston chambers 42 and 44 at the points they communicate with the passageway for reasons more apparent hereinafter. Interconnecting these transverse passageways is a longitudinally extending main passageway 96 having three regulating valves 98, 100 and 162 of the needle valve type. The regulating valve 98 is positioned in the main passageway 96 at a point between where passageways 88 and 90 communicate with the main passageway 96. The regulating valve is positioned in the main passageway 96 at a point between where passagew-ays 90 and 92 communicate with the main passageway 96. The regulating valve 102 is positioned in the main passageway 96 at a point between where passageways `92 and 94 communicate with the main passageway 96.

The regulating valve 98 comprises an annular sleeve 104 having a radially extending hole 106 communicating with the main passageway 96 when the sleeve is inserted into and suitably held by the housing 40. A needle valve 108 is rotatably mounted in the sleeve 104 and may be rotated by a screw driver or the like to vary the size of the opening through which the fluid moving in the main passageway 96 must pass at this point. The regulating valves 100 and 102 are constructed similarly to the regulating valve 98 for the same flexibility of control.

It will be understood ythat the regulating valves 98, 100 and 102 illustrated and discussed herein merely represent an example of the type of regulating valve to be employed in the door closer 20 and that any other type of regulating valve which would aflord 4the same result may be employed without departing from the spirit of the present invention.

One end of a by-pass passageway 112 communicates with the passageways 96 and 88, the other end communicating with the main passageway 96 between regulating valves 100 and 102. A ball or check valve 114, a oneway valve, is located in the by-pass passageway 112. One end of a by-pass passageway 116 communicates with the passageways 96 and 94, the other end communicating with the main passageway 96 between the regulating valve 102 and the point where the by-pass passageway 122 communicates with the main passageway 96. A ball or check valve 118, a one-way valve, is located in the by-pass passageway 116. Plugs 120 and 122 in housing 40 provide access to the check valves 114 and 118, respectively.

A reservoir passageway 124 communicates with the longitudinal main passageway 96 between the regulating valves 100 and 102. The reservoir passageway 124 communicates with a reservoir 126 within the housing 40 and is utilized to compensate for fluid displacement inequalities from the piston chambers 42 and 44 in a manner more apparent hereinafter.

The door closer 20 is shown in FIGURES 2 `and 3 at rest; that is, when the door is closed.` When the door 22 is opened the shaft 34 and the gear 62 are rotated in a counterclockwise direction, thereby rotating the gear 64 in a clockwise direction. Acting against the force exerted by the spring 84, the pistons 46 and 48 move to the right as illustrated in FIGURE 4, the arrows on the pistons indicating their direction of travel. This is the initial dooropening stage which continues until the pistons have closed off the passageway 92. FIGURES 4 and 4A illustrate the flow of the fluid displaced by the pistons 46 and 48 from their piston chambers during this initial dooropening stage. Specifically during this stage the hydraulic fluid is displaced from both chambers 42 and 44 into the passageway 92 and the main passageway 96. The general flow of fluid will, of course, be through the path of least resistance. Therefore, the fluid flows through the by-pass passageway 112 and check valve 114. to passageway 88 from which it will-enter piston chambers 42 and 44 on the trailing side of pistons 46 and 48, respectively. This is the path of least resistance since the check valve 114 places little, if any, restriction upon the fluid flow as compared to either regulating valves 98 or 100.

During this stage the pistons 46 and 48 will displace from their piston chambers more uid than may be recycled through the valving arrangement 41 to these piston chambers on'the other side of the pistons. The reason for this is that the piston shafts 50 and 52' occupy some of the piston chambers 42 and 44 on the trailing side of the pistons. Therefore, the fluid in excess of 'that required to keep the piston chambers lfilled is forced into the reservoir passageway 124 and travels to the reservoir chamber 126.

As the door continues to open the pistons 46 and 4S A and 44 through the valving arrangement 41 during the back check stage is illustrated in FIGURES 5 and 5A by the arrows. As the pistons move toward the right during 6 this stage, specifically since the passageway 92 is blocked, the fluid displaced from the chambers 42 and 44 must exit through passageway 94. Some of this displaced fluid flows into the 'by-pass passageway 116 to close the check valve 118, the direction of fluid flow in by-pass passageway 116 during this stage being opposite to that direction of flow permissible through the check valve 118. The general flow of fluid is through the main passageway 96 and the regulating valve 102, anv obstacle the fluid did not have to pass through during the initial door-opening stage. Once the fluid has passed through .the regulating valve 102 it passes through the by-pass passageway 112 to the passageway 88 and the chambers 42` and 44 on the trailing end of the pistons 46 and 48. Furthermore, that displaced fluid which the piston chambers 42 and 44 cannot accommodate will flow through the reservoir passageway 124 to the fluid reservoir chamber 126.

During the back check stage, therefore, fluid displaced from the piston chambers 42 and 44 by the pistons 46 and 48 to the trailing side of the piston chambers 42 and 44 must flow through the regulating valve 102, a resistance to flow which was not present during the initial door-opening stage. In this manner once the door 22 has been opened through a predetermined arc its opening speed will be reduced and greater pressure will be required to open the door further.

When the door is released in the open position, the force exerted by the spring 84 closes the door 22. This is effected because the spring 84 acts upon the piston 48 which in turn causes rotation of the gears 62 and 64 and. the shaft 34 whereby the door 22 closes through the action of the connecting arm 30 described hereinbefore.

During the general speed stage the pistons 46 and 48 begin to move to the left under the influence of the spring 84. Their position during this stage is illustrated by FIG- URE 6, the arrows on the pistons indicating their direction of: travel. The path the displaced fluid travels during this stage is indicated by the arrows in FIGURES 6 and 6A. Specifically, fluid is displaced from the piston chambers 42 and 44 into the passageways 88 and 90. The fluid in the passageway 88 flows into the by-pass passageway 112 and will close the check valve 114. The general flow of fluid from the forward side of the pistons 46 and 48 to Ythe trailing side of these pistons is through the passageway 90, the main passageway 96 and the regulating valve to the by-pass passageway 116 where it passes through the check valve 118 and enters the piston chambers through the passageway 92. During this stage fluid from the reservoir 126 flows through the reservoir passageway 124 to the main passageway 96 to supply the difference between the fluid displaced from the piston chambers and the fluid required to fill the trailing side of these piston chambers.

This general speed stage continues veven when the pistons 46 and 48 have passed the passageway 92 and the displaced fluid and the supplemental fluid from the reservoir 126 have two passageways, namely, passageways 92 and 94, in which to flow to the piston chambers on the trailing side of the pistons 46 and 48.

If the general speed stage has been adjusted for rel-atively fast door closing, the speed of the door 22 will be too great for it to latch in the door frame without slamming with a 'loud banging noise. To prevent this it' is desirable to slow down the speed of the door 22 as it approaches the latch in the door frame. However, this must be done in such a manner that the door will still move fast enough to assure proper latching. The door closer 20 of the present invention accomplishes both thesev objectives by adjusting the valving arrangement 41, and more specifically the regulating valve 98, to effect the latching speed stage discussed briefly hereinbefore. 'I'he general speed stage ends and the latching speed stage begins when the pistons 46 and 48 block ofl the passageway 90, as shown in FIGURE 7.

During the latching speed stage the fluid displaced from the piston chambers 42 and 44 flows in the paths indicated by the arrows in FIGURES 7 and 7A. Specifically, during this stage the hydraulic fluid is forced into the passageway 88. A portion of the fiuid flows into the bypass passageway 112 wherein it closes off the check valve 114. The general flow of the hydraulic fluid is through the main passageway 96 and it must flow through the regulating valve 98 as it travels to the passageways 92 and 94 from which it is returned to piston chambers 42 and 44 on the trailing end of the pistons 46 and 48. Since the regulating valve 98, in this instance has been adjusted to create a smaller opening than that of the regulating valve 100, the flow -of fluid from the forward side of the pistons to piston chambers 42 and 44 on the trailing side of the pistons is reduced. This in turn reduces the speed of the pistons and, therefore, effects a substantial reduction in the speed of the closing door 22 during this stage. As in the general door closing stage, iiuid from the reservoir 126 supplements that displaced from the piston chambers 42 and 44. The latching speed stage continues when the piston heads 46 and 48 move past the passageway 90 and terminates when the door 22 is securely latched in the door frame 28. Therefore, the door 22 will latch into the door frame without slamming.

The door closer may be adjusted to achieve, among other things, a slow closing speed during the gene-ral speed stage such that it is necessary to increase the speed of the door 20 just before it reaches the door frame to assure proper latching, i.e., a quick release stage. The regulating valve 100 is adjusted whereby it affords a relatively small opening for the passage of fiuid therethrough. In like manner the regulating valve 98 is adjusted whereby its opening is larger than that of the regulating valve 100. This has no effect on the initial door-opening stage and back check stage discussed hereinbefore. Now, however, during the general speed stage, though the flow path of the fluid is not altered, the regulating valve 100 only permits the door 22 to close slowly.

In this instance, the general speed stage continues until the pistons 46 and 48 have moved to the left sufiiciently to allow fluid to fiow from the passageway 90 through the channel 91 to the trailing end of the pistons 46 and 48, as illustrated in FIGURE 8. Then the quick release stage begins, the liow of fiuid during this quick release stage being illustrated in FIGURES 8 and 8A.

In the quick release stage of the door closing operation the hydraulic fluid is forced into the passageway 88 and through the main passageway 96, the regulating valve 98, the passageway 90 andthe channels 91 to the piston chambers 42 and 44 on the other side of the pistons 46 and 48. Since the fiuid need only pass through the regulating valve 98, the door 22 is allowed to speed up during this stage sufficiently to assure proper latching.

It will be readily understood that the regulating valves 98, 100 and 102 may be adjusted to increase or decrease the speed ofthe door 22 during the various stages of the door operation that they control and, furthermore, that the door closer 20 allows the general speed stage to be followed |by a latching speed stage or a quick release stage dependent upon the speed of the door during the general speed stage.

FIGURES 9 and 10 are fragmentary views of a modified door closer 160 of the present invention. The door closer 160 operates in the same manner as the door close-r 20 and differs therefrom only with respect'to its construction. Those components of the door closer 160 which are identical to the components of the door closer 20 described hereinbefore are indi-cated by the same reference numeral. The modified door closer 160 has a reservoir 156 which is similar to the reservoir 126 except that it extends between the piston chambers 42 and 44 and opens to the outside of the door closer 160. Walls 142 and 144 separate the reservoir 156 from the piston chambers 42 and 44, respectively. The reservoir 156 is close-d off by a valve cartridge 150 which may be inserted between the walls 142 and 144. The valve cartridge 150 contains transverse passageways 128, 130, 132 and 134 which are aligned with radially exten-ding holes in the walls 142 and 144 of piston chambers 42 and 44, respectively, to form passageways identical to passageways 88, 90, 92 and 94, described hereinbefore. Likewise the cartridge 150 has a main longitudinal passageway 96 which communicates with the passageways 128, 130, 132 and 134. The valve cartridge 150 contains the bypass passageways 112 and 116 an-d the check valves 114 and 118, respectively, which have been discussed hereinbefore with relation to the ldoor closer 20. The housing 40 of the door closer 160 has holes therein which may be aligned with passageways in the cartridge 150 for the insertion-of the regulating valves 98, and 102 in their respective locations in the main passageway 96. Plugs 136 and 138 close off by-pass passageway 112 and the main longitudinal passageway 96, respectively, while the housing 40 closes off the other passageways necessitated during drilling of the cartridge 150 to form Ithe various passageways requisite for the valving arrangement of the instant invention. The cartridge 150 may be held in place by any suitable means not shown, an O-ring 140 preventing any leakage from the cartridge to the -exterior ofthe closer.

The valving cartridge is preferably cylindrically shaped, but it will be understood that it may have a square or rectangular transverse cross-section if desired.

FIGURES 1l and 12 illustrate a modified construction of a piston which will float in the piston chambers 42 and 44 and achieve the same desirable results as the pistons 46 and 48 discussed hereinbefore. The modified piston, indicated generally by reference numeral 200, comprises a cylindrical piston head 202 having a longitudinal bore 204 which extends partially through the piston head 202. The piston head 202 lhas an outside diameter so that it is maintained in a substantially iiuid tight engagement with the walls of the piston chamber. A pistou shaft 206, similar to the piston shafts 50 and 52 with the exception that it need not have a projection or stud on the end thereof, extends into Ithe bore 204 of the piston head 202. The ldiameter of the bore 204 is slightly larger than the diameter of the piston shaft 206.

The piston head 202 has two aligned, radially extending holes 208 and 210. The end of the piston shaft 206 has a radially extending hole 212 which is slightly elongated in the transverse direction of the piston shaft 206. A pin 214 extends through the hole 212 and is held in 4place at its ends in the holes 208 and 210 in the piston head 202. In this manner the piston head 202 is free to move slightly radially and/ or slightly rotate on the piston shaft 206. Longitudinal movement of the piston head 202 on the piston shaft 206 is precluded because the longitudinal dimension :of the hole 212 is substantially the same as the diameter of the pin 214. The piston head 202 therefore fioats on the piston shaft 206 and will properly position itself within the piston chambers even if the piston chambers are not aligned concentrically with the bore in which the piston shaft206 is located.

While several embodiments described herein are at present considered to be preferred, it is understood that various modifications and improvements may be made therein, and it is intended to cover in the appended claims all such modifications and improvements as fall within the true spirit and scope of the invention.

What is desired to be claimed and secured by Letters Patent of the United States is:

1. A door closer adapted to be [operatively connected to a door to control the opening and 'closing of the door which comprises ra housing having ya piston chamber, a piston operatively movable in said piston chamber where- Iby movement of lsaid piston in said piston chamber forces diuid from said piston chamber through :a vala/ing arrangement in said housing t-o control the speed at which the door opens and closes, and valving arrangement comprising a group of passageways within said housing, each of said p-assageways in -said group communicating with said piston chamber -at spaced points along the longitudinal axis of said piston chamber, a main passageway in said housing communicating with each olf said passageways in said group, said main passageway having a valve therein, a by-pass passageway having ends which communicate with said main passageway on opposite sides tot said valve in said main passageway, said by-pass passageway having a tone-'way valve therein, said one-way valve permitting iluid to flow through said by-pass passageway in Ionly one direction, said group of passageways comprising a first passageway, a second passageway, a third passageway and a Ifourth passageway each off which communicates with said piston chamber and said main passageway at different points along its longitudinal axis, said first and fourth passageways communicating with said piston chamber at .opposite ends of the movement of said piston in said piston cham-ber, said main passageway havin-g a first valve and a second valve therein, said first valve being positioned between Where lsaid first passageway and said second passageway communicate with sai-d main passageway, said second valve being positioned 4between where said second passageway'and -said third :passageway communicate with said main passageway.

l2. The door `closer of claim 1 wherein said housing has a reservoir chamber, vsaid reservoir chamber communicating with said main passageway.

3. The door closer of claim 1 wherein a third valve is positioned within said main passageway between where said t-hird passageway and said fourth passageway cominunicate with said main passageway, a second by-pass .i

tending piston chambers, a piston operatively'moveable in each of said piston chambers, whereby movement of the pistons in one `direction forces uid rom said piston chambers through a valving arrangement in said housing to control the speed at which the door 'opens and closes, said valving arrangement comprising a group of passageways within said housing, said group of -passageways .comprising a first passageway, Ia second passageway, a

third passageway and a fourth passageway, each oct said passageways in said group communicating with both of said piston chambers Aat spaced points along the longitudinal 4axis of said piston chambers, said first passageway communicating with one end of each of said piston chambers 4and said fourth passageway communicating with the other ends of said piston chambers, a main passageway within said housing communicating with each of said passageways in said group, said main passageway having a first valve and a Second valve therein to control the flow of uid through said main passageway, said first valve being positioned between where said iirst passageway and said second passageway communicate with said main passageway, said second valve being positioned between where said second passageway and said third passageway communicate with said main passageway, and Ia lby-pass passageway having ends which communicate with said main passageway on opposite sides of said first `and second valves in said main passageway, said by-pass passageway having a one-way valve therein, said oneway valve permitting tluid to flow through said by-pass passageway in only `one direction.

6. A door closer adapted to be operatively connected to a door =to control the opening and closing ef .the door which comprises :a -housing having two longitudinally extending piston chambers, a piston operatively movable in each ott said piston chambers, whereby movement of the pistons in one direction forces fluid from said piston chambers through a valving :arrangement in said housing to control the speed at which the door opens and closes, said valving arrangement comprising a group of passageways within sai-d housing, said group of passageways comprising a iirst passageway, a se-cond passageway, a third passageway and a .fourth passageway, each of said passageways in said group communicating with both of said piston chambers at spaced points along the longitudinal axis of said piston chambers, said first passageway communicating with yone end of each of said piston chambers and said fourth passageway communicating with the other ends of said piston chambers, said main vpassageway having a irst valve, a second valve and a third valve therein to control the iiow of fiuid through said main passageway, said first valve being positioned between where said first passageway and said second passageway communicate with said main passageway, said second valve being positioned between where said second passageway and said third passageway communicate with said main passageway, said third valve being positioned where said third passageway and said [fourth passageway communicate with said ymain passageway, a fiirst by-pass passageway having ends which communicate with said main passageway on opposite sides of said first and second va-lves in said main passageway, one end of said first by-pass passageway comunicating with said main passageway between said second and ,third valves, a second `by-pa-sspassageway communicating with said main passageway lon opposite sides of said third valve, one end of sai-d second by-pass passageway communicatin-g with said main passageway between -said second .and third valves in said main passageway, said rst and second by-pass passageways each having a one-way valve therein, said Ione-way valve permitting :duid -to iiow through said bypass passageways in only one direction.

7. The door closer of claim 6 wherein said valving arrangement is in a cartridge which lmay be inserted into said housing between said piston chambers.

8.- The door cl-oser of claim 6 wherein said housing has a reservoir chamber communicating with said main passageway between said second and third valves.

9. In a door closer of the iiuid checking type including a piston Iarrangement wherein said piston is connected to a piston shatt, said piston operating within a piston chamber in said 'closer and said pist-on shaft operating in a bore within said closer which communicates with said piston chamber, the improvement comprising a cylindrical piston head, said piston-head having a longitudinal bore extending partially therein, said piston shaft extending into said bore of said piston head, said bore 'of said piston head having a larger diameter than the diameter of said piston shaft, said piston head having two aligned radially extending holes therein and said piston shaft having a .radially extending hole there-through, a pin extending through said hole in said piston shaft and Ibeing rfixed in place by said holes in said piston head, said hole in said piston shaft being elongated in a trans- Verse direction and having a `longitudinal dimension substantially the same as the ydiameter of said pin, the ends 'of said pin being secured intosaid two holes of said piston head to prevent longitudinal movement ci said p-iston head while permitting said piston head to move radially and rotatably about said piston shaft.

10. A door closer adapted to be operatively connected to a door to control the opening and closing of the door which comprises a housing having a piston chamber, a piston operatively movable in `said piston chamber whereby movement of said piston in said piston chamber forces `fluid from said piston chamber thorugh a va-lving anrangement in said housing, said lpiston preventing flow off fluid in said .piston `chamber past said piston and forming lirst and second zones in said piston chamber, said valving arrangement including first -and second passageways in said housing communicating with said lirst and second zones, a iirst adjustable valve means in said irst passage- Way for controlling the ilow of fluid from Asaid ltrst zone to said `second zone as said piston moves in one direction when said 4door opens whereby said tirst valve means control-s the speed at which said door `opens and a second adjustable valve means in said second passageway for controlling the llow 'of fluid Ifrom said second zone to said iirst zone as said piston moves in the opposite di- -rection when said door closes whereby said second rvalve means controls Athe speed at which said door closes, valve means in said first passageway to prevent the 110W of -fluid therethrough when s-aid door is closing and 'valve means in said second passageway to prevent the flow of lluid therethrough when said door is opening.

References Cited by the Examiner UNITED STATES PATENTS 1 2. 1,121,084 `12/1914 Finken 16-62 1,147,909 7/ 1915 Williams 16-62 =1,513,606 10/ 1924 Kreamer 2511-86 1,674,756 6/1928 Wuchert 16-62 2,460,369 2/f1949 Stronac-h 16-56 2,682,625 .6/ 1954 Storeng 287-20 2,723,416 1'1/1955 S'hclage 16-52 2,731,314 1/ 1956 Doeg 287-20 2,797,029 6/ 1957 Beaver 287-20 2,899,701 8/ 1959 Schroeder 16-64 3,040,372 6/ 1962 'Ellis 16-62 3,042,957 7/1962 Muessel 16-62 FOREIGN PATENTS 14,998 2/ 1904 Austria.

1,002,219 2/ `195 7 Genmtany.

275,356 5/195-1 Switzerland.

284,687 a12/ 1952 Switzerland.

314,590 8/ 195 6 Switzerland.

JOSEPH D. SEERS, Primary Examiner.

DONDEY I. STOCKING, Examiner.

B. G'BLAK, D. L. BURGESS, B. R. GAY,

' Assistant Examiners. 

1. A DOOR CLOSER ADAPTED TO BE OPERATIVELY CONNECTED TO A DOOR TO CONTROL THE OPENING AND CLOSING OF THE DOOR WHICH COMPRISES A HOUSING HAVING A PISTON CHAMBER, A PISTON OPERATIVELY MOVABLE IN SAID PISTON CHAMBER WHEREBY MOVEMENT OF SAID PISTON IN SAID PISTON CHAMBER FORCES FLUID FROM SAID PISTON CHAMBER THROUGH A VALVING ARRANGEMENT IN SAID HOUSING TO CONTROL THE SPEED AT WHICH THE DOOR OPENS AND CLOSES, AND VALVING ARRANGEMENT COMPRISING A GROUP OF PASSAGEWAYS WITHIN SAID HOUSING, EACH OF SAID PASSAGEWAYS IN SAID GROUP COMMUNICATING WITH SAID PISTON CHAMBER AT SPACED POINTS ALONG THE LONGITUDINAL AXIS OF SAID PISTON CHAMBER, A MAIN PASSAGEWAY IN SAID HOUSING COMMUNICATING WITH EACH OF SAID PASSAGEWAYS IN SAID GROUP, SAID MAIN PASSAGEWAY HAVING A VALVE THEREIN, A BY-PASS PASSAGEWAY HAVING ENDS WHICH COMMUNICATE WITH SAID MAIN PASSAGEWAY ON OPPOSITE SIDES OF SAID VALVE IN SAID MAIN PASSAGEWAY, SAID BY-PASS PASSAGEWAY HAVING A ONE-WAY VALVE THEREIN, SAID ONE-WAY VALVE PERMITTING FLUID TO FLOW THROUGH SAID BY-PASS PASSAGEWAY IN ONLY ONE DIRECTION, SAID GROUP OF PASSAGEWAYS COMPRISING A FIRST PASSAGEWAY, A SECOND PASSAGEWAY, A THRD PASSAGEWAY AND A FOURTH PASSAGEWAY EACH OF WHICH COMMUNICATES WITH SAID PISTON CHAMBER AND SAID MAIN PASSAGEWAY AT DIFFERENT POSINTS ALONG ITS LONGITUDINAL AXIS, SAID FIRST AND FOURTH PASSAGEWAYS COMMUNICATING WITH SAID PISTON CHAMBER AT OPPOSITE ENDS OF THE MOVEMENT OF SAID PISTON IN SAID PISTON CHAMBER, SAID MAIN PASSAGEWAY HAVING A FIRST VALVE AND A SECOND VALVE THEREIN, SAID FIRST VALVE BEING POSITIONED BETWEEN WHERE SAID FIRST PASSAGEWAY AND SAID SECOND PASSAGEWAY COMMUNICATE WITH SAID MAIN PASSAGEWAY, SAID SECOND VALVE BEING POSITIONED BETWEEN WHERE SAID SECOND PASSAGEWAY AND SAID THIRD PASSAGEWAY COMMUNICATE WITH SAID MAIN PASSAGEWAY. 